Op-art architecture designed for happiness.

Baroque celebration of the end of the Great Plague of Vienna.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

A subterranean house of worship carved right out of the bedrock.

This irregularly shaped sea fortress has defended not one but three different sovereign states.

A small island dotted with old, historic Finnish buildings.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

Giant marble phalluses on the sacred island of antiquity.

Replicas of Apollo's leonine stone guard cats still line a sacred row in Greece.

Scores of wax baby figurines add an unusual mood to this beautiful church on the Greek coast.

Go inside to really appreciate this 500-year-old technological masterpiece.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Where Venice's gondolas go for a tune-up.

This micro-nation may be some sort of prank, but its constitution sure seems official.

Travelers who fall victim to this mermaid's charms are destined to stay in Užupis forever.

A 300-kilogram egg sculpture that embodied a neighborhood revival.

A black cat protests the City Guild in Riga's Old Town.

A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

3,000 market stands in five former Zeppelin hangars.